The present invention relates to fuseholder assemblies, and more particularly to a means for polarizing a multi-pole fuseholder assembly for in-line fuses.
Multi-pole fuseholders for supporting a plurality of in-line electric fuses in spaced apart relation are well known in the art. See for example Urani, U.S. Pat. No. 3,710,296 which is assigned to the assignee of the present invention. A two pole fuseholder such as that shown in the Urani patent may include individual line side and load side sections secured together in spaced relation by a separate supporting structure. The supporting structure may include a line side plate releasably fastened to a load side plate for respectively receiving the line side and load side fuseholder sections. Alternately, the respective fuseholder sections and their supporting plates may each be molded as an integral unit so that the two sides "make" or "break" contact simultaneously.
In some applications of two pole fuseholders a dummy fuse may be used in the grounded pole. In such an application, if the fuseholder sections are disassembled and then inadvertently reassembled so that the dummy fuse is in the hot pole there is no protection for the load. As a result, the load may be exposed to damage in the event of an overload or short circuit. It is thus desirable to provide a means for polarizing the load and line side sections of a fuseholder to prevent improper assembly.
Two pole fuseholders utilizing a dummy fuse may also be used in connection with a breakaway receptacle used as a mechanical weak link to physically interrupt the circuit under impact. The breakaway feature is desirable for application in breakaway lighting standards as required by State and Federal highway regulations. When assembled, a male line side fuseholder terminal makes sliding contact with a female receptacle terminal, and it is this contact which parts under impact to break the circuit. As a result, it is also necessary to properly assemble the fuseholder and breakaway receptacle with respect to one another so that a dummy fuse is not inadvertently placed in the hot pole of the receptacle. It is thus desirable to provide polarity between the fuseholder and the breakaway receptacle to insure proper assembly.